NATURE: World's Slowest-Moving Drop Caught on Camera at Last

Begun in October 1944, the Tar Drop experiment, at Trinity College Dublin's School of Physics, is one of the world's oldest continuously running experiments.

This curiosity of an experiment demonstrates that tar, or pitch, is a material that flows - albeit it with an incredibly high viscosity. Whilst pitch has been dropping from the funnel since 1944, nobody has ever witnessed a drop fall - they happen it happens roughly only once in a decade!

In May of this year, with the latest drop about to fall, Prof. Shane Bergin broadcast the experiment via the web. On July 11th, the drop dripped. You can see a time lapse video of this here.

Tracking the evolution of the drop, Profs. Weaire & and Hutzler, and Mr. David Whyte calculated the viscosity of the pitch to be 2x107 Pa s - approximately 2 million times the viscosity of honey.

Time-lapsed video of the Pitch-Tar Drop experiment:

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How long would you be willing to wait for a drop of the black stuff in Dublin?

After 69 years, one of the longest-running laboratory investigations in the world has finally captured the fall of a drop of tar pitch on camera for the first time.